In low-temperature dryers, especially compressed air low-temperature dryers, for drying of a gaseous working fluid during cooling of a gaseous working fluid using a refrigerant, the working fluid initially passes through a pre-heat exchanger section and then a main heat exchanger section. Cooling of the working fluid fed to the low-temperature dryer occurs in the pre-heat exchanger section by the dried and cooled working fluid in the countercurrent principle. The working fluid is further cooled by a refrigerant in the main heat exchanger section, so that moisture is condensed out from the working fluid and can be withdrawn.
A low-temperature dryer according to the prior art is described, for example, in DE 100 30 627 A1.